Bushing for knock out pin and removable knock out pin assembly

Abstract

A bushing for retaining a knock out pin and a removable knock out pin assembly utilizing that bushing. The bushing has a pin holding portion composed of upstanding flexible arms engagable with a knock out pin, each of the arms having a lug for engaging the knock out pin. A retention ring is formed on the bottom of the bushing, the ring having an outwardly-extending flange for engaging an aperture in a plastic mold. The knock out pin has opposite grooves for accommodating the lugs of the bushing, the pin being removable by rotating the pin 90° to disengage the lugs from the grooves so that the pin can be axially removed.

What is claimed is: 
     
       1. A bushing for retaining a knock out pin for a plastic mold, comprising a. a pin holding portion, said pin holding portion including flexible means for gripping a knock out pin to hold the knock out pin in place in said pin holding portion, and   b. means for retaining the bushing in a plastic mold.   
     
     
       2. A bushing according to claim 1, in which said bushing includes a shank, said pin holding portion being located at one end of said shank and said retaining means being located at an opposite end of said shank. 
     
     
       3. A bushing according to claim 2, in which said shank includes opposite arms, and said retaining means comprises a ring having a circumferential flange. 
     
     
       4. A bushing according to claim 1, in which said flexible means includes opposed grip members for engaging a knock out pin, said grip members extending from opposite flexible arms spaced from one another to accommodate a knock out pin. 
     
     
       5. A bushing according to claim 4, in which said grip members comprise lugs. 
     
     
       6. A removable knock out pin assembly for a plastic mold, comprising a. a bushing, said bushing including i. a pin holding portion, said pin holding portion including flexible means for gripping a knock out pin to hold the knock out pin in place in said pin holding portion,   ii. means for retaining the bushing in a plastic mold, and     b. an elongated knock out pin, said pin being grippable by said flexible means and being removable from said pin holding portion by disengagement from said flexible means.   
     
     
       7. A removable knock out pin assembly according to claim 6, in which said bushing includes a shank, said pin holding portion being located at one end of said shank and said retaining means being located at an opposite end of said shank. 
     
     
       8. A removable knock out pin assembly according to claim 7, in which said shank includes opposite arms, and said retaining means comprises a ring having a circumferential flange. 
     
     
       9. A removable knock out pin assembly according to claim 6, in which said flexible means includes opposed grip members for engaging a knock out pin, said grip members extending from opposite flexible arms spaced from one another to accommodate a knock out pin. 
     
     
       10. A removable knock out pin assembly according to claim 9, in which said grip members comprise lugs. 
     
     
       11. A removable knock out pin assembly according to claim 9, in which said knock out pin includes opposite means for accommodating said grip members. 
     
     
       12. A removable knock out pin assembly according to claim 11, in which said means for accommodating comprises opposite grooves in said knock out pin. 
     
     
       13. A removable knock out pin assembly according to claim 12, in which said knock out pin is removable from said pin holding portion by means of rotation of said knock out pin about a central axis to disengage said grip members from said opposite grooves. 
     
     
       14. A removable knock out pin assembly according to claim 12, in which said grip members comprise lugs engaging said opposite grooves.